The U.N. Human Rights Council reviews Nigeria's human rights record Monday, an assessment that is conducted every four years of all member states. Rights groups say Nigeria faces critical human rights challenges, but the government disputes many of those claims.

Human rights groups, including Amnesty International and Human Rights Watch, expect Nigerian government officials to be questioned about issues including torture, illegal killings by security agents, the death penalty and prison conditions. Also likely to be discussed are a bill currently before the Nigerian parliament seeking to ban gay marriage and punish same-sex couples, and the crisis in the oil-rich Niger Delta.

Abuja-based lawyer and human rights activist, Olawale Fapohunda, says most of the inmates in Nigeria's overcrowded prisons have not yet been charged with any offense.

"We have multiple issues with prisons," said Olawale Fapohunda. "We have about 39,000 inmates. We have 227 prisons. Of the 39,000 inmates, about 26,000 are awaiting trial inmates. About 11,000 have been in prison for five years and above, awaiting trial. We have about 800 inmates on death row; more than 200 of them have been on death row for over 10 years."

Amnesty International says its investigations revealed that the Nigerian police routinely tortured detainees in order to extract confessions. About 80 percent of prison inmates said they had been beaten by police, threatened with weapons and tortured in police cells. Amnesty International says torture was widespread and systematic.

The Nigerian government in its reports to the Human Rights Council, ahead of Monday's session, says torture was not widespread in Nigeria.

Amnesty International says the Nigerian government has to look at its human rights problems with a critical eye to make real improvements for the people of Nigeria.

Nigerian government officials will be questioned concerning the country's human rights record, then hear recommendations for improvement. The discussion on Nigeria is part of a global human rights review.